A torque limiter is installed between a rotary drive member and a rotary driven member, acts as a joint and, in addition to transmitting twisting torque, determines a maximum twisting torque transmittable by the rotary drive member to the rotary driven member, so as to disconnect the two members when the maximum twisting torque is exceeded.
As shown in FIG. 3, currently used torque limiters comprise
a hub A fitted to a rotary drive shaft B;
a first flange C fixed to the hub by a number of screws D;
a second flange (not shown) fitted to a rotary driven shaft (not shown); and
a number of modules E for transmitting motion between the two flanges, and for disconnecting the flanges when a maximum transmitted twisting torque is exceeded.
At present, screws D fastening the first flange C to hub A are located along an annular portion smaller in diameter than that along which modules E are located. So, to connect the rotary driven member to a rotary drive member with a rotary shaft of a different, e.g. larger, diameter, the entire torque limiter, including the second flange fitted to the rotary driven shaft, must be changed. And, since torque limiters of this type are used in very large structures, changing the torque limiter means moving one of the two structures, with all the problems the size of the structures poses.